Methods and means for forming spring pads



March 15, 1960 J. HECKETHQRN 2,928,433

METHODS AND MEANS FOR FORMING SPRING PADS Filed Feb. 7, 1957 4 Sheets-Sheet l fNVENTOR.

ATTORNEY March 15, 1960 J. E. HECKETHORN METHODS AND MEANS FOR FORMING SPRING PADS Filed Feb. 7, 1957 John E.

4 Sheets-Sheet 2 INVENTOR.

Heckethorn ATTORNEY March 15, 1960 J HECKETHORN 2,928,433

METHODS AND MEANS FOR FORMING SPRING PADS 7 Filed Feb. 7, 1957 4 Sheets-Sheet 3 Fig. 5

INVENTOR. John E. Heckemnrn ATTORNEY March 15, 1960 J. E. HECKETHORN 2,928,433

' METHODS AND MEANS FOR FORMING SPRING PADS Filed Feb. 7, 1957 4 Sheets-Sheet 4 Emu m l\ z m INVENTOR'T' 2 John E. Heckethorn ATTORNEY United States atent O METHODS AND MEANS FOR FORMING SPRING PADS John E. Heckethorn, Denver, Colo., assign'or to Heckethorn Manufacturing & Supply Co., Dyersburg, Teun., a corporation of Colorado Application February 7, 1957, Serial No. 638,728

6 Claims. (Cl. 1403) This invention relates to the manufacture of spring pads for use in spring cushions of the type in which the resiliency is imparted by means of entwined, longitudinally-extending, spirally-coiled springs. Such pads provide cool, soft, resilient, auxiliary seat and back cushions for use in automobiles, boats, grandstands, and the like and for general portable seat uses.

The principal object of the invention is to provide a method and means which will rapidly and efliciently entwine and install the coiled springs in an enclosing frame to form a complete, unitary spring pad for use in the spring cushion.

Another object of the invention is to provide a platen for efficiently supporting a plurality of tubular coiled springs and which will magnetically retain the coiled springs in place during the entwining operation.

A further object is to provide a spring'pad forming machine which can be applied to and used in connection with any of the conventional continuous spring forming machines for receiving and accurately entwining the springs as they are formed by the forming machine.

The improved assembling machine is more particularly designed for use in connection with the attachment for spring-forming machines but is not limited to this particular application. V v

Other objects and advantages reside in the detail construction of the invention, which is designed for simplicity, economy, and efficiency. These will become more apparent from the following description.

In the following detailed description of the invention reference is had to the accompanying drawing which forms a part hereof. Like numerals refer to like parts in all views of the drawing and throughout the description.

In the drawing:

Fig. l is a plan view, partially broken away, illustrating a spring cushion containing a spring pad of the type to which the present invention is adaptable;

Fig. 2 is an enlarged cross-section of the cushion of Fig. 1, taken on the line 22;

Fig. 3 is a diagrammatic rear view of a spring forming machine illustrating a method whereby this improved pad forming machine may be driven;

Fig. 4 is a plan view of the improved spring pad forming machine, illustrating, in broken line, the position of a conventional spring forming machine thereon;

Fig.5 is a rear elevationalview thereof;

Fig. 6 is an enlarged, fragmentary, detail view, partially broken away, illustrating a portion of the upper surface of a magnetic platen employed in the improved spring pad forming machine with coiled springs in place thereon;

Fig. 7 is a fragmentary cross-section, taken on the line 7-7, Fig. 6;

Fig. 8 is a vertical cross-section through the machine, taken on the line 8-8, Fig. and

Figs. 9 and 10 are enlarged detail sections, taken on the lines 99 and 10-10, respectively, Fig. 8.

The construction of a spring cushion in the manufacture of which the present invention is employed is illus- 2,928,433 Patented Mar. 15, 1960 plurality of tubular spirally-wound springs 10 positioned in parallel entwined relation within an outer quadrilateral rod frame 11 to form a flat resilient'spring pad. The cushion is completed by placing the spring pad in a flexible outer cover or slip 12.

The springs may be formed on any type of spring forming machine designed to form wire into a spiral which is continuously extruded from the machine. Such a machine is illustrated and described in applicants copending application and the position thereof relative to this pad forming machine is indicated at 49. vSuch a machine delivers a coiled spring horizontally from a winding mandrel 50 and is provided with a cutoff shaft 60 which reciprocally rotates to actuate a wire cutting mechanism which severs the spring wire at the termination of each spring. This improved pad-forming machine is designed to receive the springs from the mandrel 50 and form them into spring pads. The pad forming machine may be driven from any suitable element of the spring forming machine. As illustrated, it is driven from the cutoff shaft 60.

The pad-forming machine employs a horizontally positioned, rectangular platen 13 formed of nonmagnetic material, such as aluminum, and provided with a plurality of parallel, spring-receiving grooves 14 extending from the front to the rear edge of its upper surface. The size of the platen and the number of grooves 14 depend, of course, upon the size of the largest spring pad to be assembled by the machine. A plurality of permanent magnets 48 are embedded in the bottom of the platen 13 and positioned below each of the grooves 14 along the center line thereof. These magnets are preferably of the bar type having a horseshoe cross-section and extending substantially the full length of the grooves 14.

The platen 13 is movably supported upon a pair of grooved rear track rollers 15 and a single ungrooved front track roller 21 positioned to travel along two parallel transversally-extending track bars 16. The track bars 16 are supported upon swingable, parallel links 17 which are mounted upon and extend upwardly from a pair of parallel base bars 18 and are maintained in spaced parallel relation by means of cross bars 22. The base bars are supported from a table plate 19 by means of suitable pillow blocks 20.

it can be seen that the above structure allows the platen 13 to be moved from side to side by' rolling it along the track bars 16 and can be moved forward and back by swinging the parallel links 17. Movement toward the right is intermittently imparted through the medium of a toothed rack bar 23 secured to the bottom of the platen 13. The rack bar is engaged by a toothed pinion 24 which is mounted on a clutch shaft 1 25 which is rotatably journalled in a suitable bearing 26 supported upon a bearing bracket 27 mounted upon the table plate 19.

7 Power is intermittently transmitted to the pinion 24 through a directional clutch 28 from an axially aligned drive shaft 29. The drive shaft 29 is supported in a suitable bearing bracket 30 and terminates in a cam follower-crank 31 provided with a follower roller 32 arthe power shaft '29 which is transmitted through the di- 7 rectional clutch 28 to the clutch shaft 25 to cause the pinion 24 to act through the rack bar 23 to move the platen 13 to the right the pitch distance between the grooves 14. The follower crank 31 will then be returned by areturrr spring-62m await the nextactuation by the actuating lever 61. The'directional .clutch'2'8 ally .engages ratchet notches 34 formed in the periphery of an interval disc 35 which is secured on the clutch shaft 25. The setting of the click pawl33, .to accuratelypositionthe platen, is accomplished by mounting the pawl in an adjustable carriage 36, the position of which can be accurately adjusted by .means'of an adjusting screw 37. The drive shaft 29 is preferablylprovided with a suitable friction clutch 64 to allow relative play between the crank 31 and the shaft 29 should the crank the stop spacing of the interval disc 35.

Thus, it can be seen that at each reciprocation of the drive shaft 29, the platen 13 will moveto'the. right the distance between adjacent grooves14.

v The platen 13 is constantlyurged to the left byrneans of a counterweight 38 which is positioned in a jack pot 39 atthe left side of the machine, and from which a tension-cable 40Jextends to a suitable cable clamp 65 on the platen 13. When the platen 13 has advanced to the right the full distance desired, the directional clutch 28 is released, such as by means of a manual release lever 41, so that the weight 38 will return the platen to its original starting position.

The platen 13 is moved-forward and backby means of a cam wheel 42 which is-athxed to the extremity of the clutch shaft 25 and rotates in .synchronism therewith. The cam wheel is provided with spaced-apartface cam grooves 43, there being one-half as many face cam grooves as there are notches 34 in the interval disc 35. The cam grooves have a depth equal to one-half the pitch of the coiled pad spring. A cam follower roller 44 is constantly urged against the face of the cam wheel 42 by means of a tension spring 47 and successively enters the grooves 43. The cam-follower roller 44 is carried on a roller bracket 45 affixed to a frame member 46 extending betweentthe forward parallellinks 17 It can be seen that each timethe -roller 44 rolls into one of the grooves '43, the platen.1'3 will moverear wardly thejdepth' of the groove, and-each timetheroller 44 rolls onto a separating space betweenthe grooves, thetplaten -lfi will be urged forwardly the groove depth. v lhe pad forming machine and thespring forming .machine are relatively positioned so that the first groove at formedrof any desired size and foriany desired use. The V names It will be noted that the grooves 14 are spaced-apart a distance less than the spring diameter to cause the springs to overlapveach other. so that they may be'readily entwined as they are wound, as shown in Fig. 7.

As above'described, a simple entwined spring mat is of which the hooks 51' may be pulled away from the platen 13; A second pair. of adjustable retaining hooks vary from is then swung to a vertical position, as indicated in broken 53 may :be'securedQin any desiredposfitionat the finishing side of the platen 13 by means .of set screws 59. A clamping bar 52 is supported on swinging levers 57 at the finishing side of the platen 13. The 'clampingbar 52 can be .swung downwardly into clamping engagement with the platen by means of a clamping lever 58.

To form a complete assembled-spring pad the platen is returned to its starting'position. v frame llfld placed inthe hooks 151 which support it in axial alignment with'the first groove14. The rod frame line .in Fig. 5, where it is temporarily retained "out of theway byrneans of a suitable, permanent magnet 66 supported abovefiheplaten 13 onamagnet bracket 67.

. The firstspringto exit'from the spring winding machine will then wind about the "side rod'of therodframe as shown inFig. 6. The winding 'of the'remaining springs will be continued in entwined relationas'above described until one lessthan'the desired number of springs has The rod 'frame 11 is now pulled away {fronrthe re- .taining magnet 66 "and allowed'to drop upo n the shafts 40' pull thehookrod 54from theplaten '13 so-asto move the entirerodfrarne to the right until its opposite side bar-engagesfin the hooks53to stop andmaintain it in the. right of theplaten will be in alignment with the mandrel 50 of the spring forming machine so that the first spring of the pad will travel along this groove in a spiral as it exits from the winding machine. When a spring of the desired length has been discharged, the-cutoff shaft: 60 of the winding machine will actuate to cut the wire. .The movement of the shaft 601willbe transmitted through the crank 31 tomove the platen 13 one space to the right to receive the next spring in the next successive groove 14. Thus,-the platen 13 will-receive the springs in successive parallel arrangement. As: each spring exits in a spiral cylindrical coil from thespring.

winding machine; it i will travel along its respective groove 14 and will be retained in that'groove by the mag? netic attraction of the groove magnet 485 Simultaneously withthe sidewardmovements'of platen the latter will alternately move forwardly and rearwardly the depth of one 'of the grooves 143 in the aiiial alignment with the finishin'g groove "14. "The last spring is now discharged fromjthespring winding machine about the side bar of the rod frame and in entwined relation tonext to the last spring to for m"the complete assembled spring pad. Thepadcan bereleased for removal by simply releasing thelevers'55 and 58. The extremitiesof thesprings are attached to the ends of the rod frainein any suitable manner such as indic'atedat 68 in Fig. 1. l

Platens of various sizes can be quickly interchanged 'on'the track bars 16 by simply lifting them'on and off swinging levers T57 and.locking it iin .lthe deSired,.posicam wheel 42, that is; a distance equal to one halfof thepitch of the springs 10, sothat as each successive spring exits from the mandrehSt), .it will enter between the windings of andentwinewith themext, previously wound spring throughout its entire length. The winding tion ..by. means at suitable .set .s crews I63 and adjusting j the position .of. the se condgpair tofihookst 53. and locking samc..by..means-o, f.-the.:setscrews '59. 1 V

While .a specific.. form of. .theiimprovement .has been describedand illustrated herein; it is tdbenndersto'od that the same may be varied within the scope of the appended spring winding machine. ofthe. type adapted to.discharge rlotating cylindrical, spirallyrwgund springs ..'for forming entwined spring pads from the springs as they dis- One side of the rod claims, withoutdeparting fromthe spiritof the-invention.

charge from said winding machine comprising: a flat, horizontally positioned platen positioned to receive the springs discharging from said spring winding machine upon its upper surface at one end of the latter; a plurality of longitudinally-extending spring receiving grooves in said upper surface arranged in paral el spaced relation across the width of said platen, said fiat platen being movable laterally in a horizontal plane so that the grooves therein may be successively brought into alignment with the discharge of said fixed spring winding machine to receive a spring from the latter, said grooves being spaced apart a distance less than the diameter of said springs so that each successive spring will overlap the preceding spring and said platen being also movable longitudinally in a horizontal plane to position the turns of each succeeding spring between the turns of the next preceding spring as it rotatively advances along its groove in said platen; shifting means connected with said platen and acting to shift said platen longitudinally and forwardly upon the completion of the winding of each alternate spring and longitudinally and rearwardly upon the completion of each interjacent spring so that the turns of each discharging spring will pass between the turns of the previously discharged spring; and parallel, horizontal track bars positioned below and transversally of said platen and supporting rollers mounted on said platen and adapted to travel along said track bars to allow movement of said platen in a horizontal plane.

2. A machine as described in claim 1 having substan tially vertical parallel links supporting said track bars and arranged to swing longitudinally of said platen to allow said track bars and said platen to be moved forwardly and backwardly in a horizontal plane to position the turns of each discharging spring between the turns of the next previously discharged spring.

3. A machine as described in claim 2 having means for moving said platen forwardly and backwardly comprising: a cam follower member connected with said parallel links; a cam Wheel; resilient means urging said follower member into contact with said cam wheel; and means for rotating said cam wheel an interval in consequence of each advance of said platen, said cam wheel being contoured to move said follower member forward at each alternate interval and rearward at each intermediate interval.

4. A machine as described in claim 3 having an elongated toothed rack secured transversally of andbeneath said platen for substantially the full width thereof-a pinion shaft positioned below and longitudinally of said platen; a toothed pinion mounted on said pinion shaft in mesh with the teeth of said rack; and means for rotating said pinion sufiiciently at the completion of the discharge of each spring to cause said rack to move said 6 platen laterally a distance equal to the, spacing of said grooves.

5. A machine for use in combination with a fixed spring winding machine of the type adapted to discharge rotating, cylindrical, spirally-wound springs, for

forming entwined spring pads from the springs as they discharge from said winding machine comprising: a flat, horizontally positioned platen positioned to receive the springs; spring receiving grooves extending longitudinally of the upper surface of said platen in spaced, parallel relation, said flat platen being movable laterally in a horizontal plane so that the grooves therein may be successively brought into alignment with the discharge of said fixed spring winding machine to receive a spring from the latter, said grooves being spaced-apart a distance less than the diameter of said springs so that each successive spring will overlap the preceding spring, said platen being also movable longitudinally in a horizontal plane to position the turns of each succeeding spring between the turns of the next preceding spring as it rotatively advances along its groove in said platen, said platen being of non-magnetic material; a magnet groove formed in the lower surface of said platen below and in alignment with each of said spring receiving grooves; and an elongated permanent magnet positioned in each of said magnet grooves and acting to magnetically maintain the springs in their respective grooves.

6. A method for forming spring pads of the type consisting of a plurality of parallel, entwined, cylindrical, spirally-wound springs comprising: causing said springs to discharge from a winding machine in succession, each spring, discharging as a tubular, advancing, revolving spiral; receiving said springs in successive grooves in a platen so that each spring will overlap and entwine with the next previously wound spring as the rotating spring advances to form a spring-like pad; maintaining the successive springs spaced-apart adistance less than their diameters during the winding and advancing so that each successive spring will overlap and entwine with the next previously wound spring; and thence stretching the entire pad transversally of the axis of said springs prior to the application of the final spring about the second side of said rod frame.

References Cited in the file of this patent UNITED STATES PATENTS 464,940 Kehr Dec. 8,1891 511,435 Kehr- Dec. 26, 1893 825,415 Pine July 10, 1906 2,603,246 Dockery July 15, 1952 2,630,145 Stevens Mar. 3. 1953 

